Acromioclavicular (AC) joint separations are one of. Treatment of the Acute Traumatic Acromioclavicular Separation REVIEW ARTICLE

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1 REVIEW ARTICLE Treatment of the Acute Traumatic Acromioclavicular Separation Julie Y. Bishop, MD and Christopher Kaeding, MD Abstract: Injuries to the acromioclavicular joint occur commonly in athletes, especially those involved in contact sports. The majority of these injuries are type I and II acromioclavicular joint separations and are treated nonoperatively with rehabilitation. A rapid and full return to play is expected. Acute types IV, V, and VI are less common and operative intervention is recommended. The type III injury is more controversial and current trends are towards initial nonoperative management. Operative treatment is sought only when the athlete remains symptomatic with painful instability. However, some do support early intervention in the overhead athlete. The goal of operative intervention is to create a stiff and strong repair/reconstruction of the coracoclavicular ligaments while providing stability in all planes. This will allow early and more aggressive rehabilitation. Surgical treatment includes reconstruction of the coracoclavicular ligaments with an augmented coracoacromial ligament transfer and more recently tendon graft reconstructions. Biomechanical research supports an anatomic reconstruction of the ligaments to confer the most function and stability. Key Words: acromioclavicular joint separation, coracoclavicular ligaments, conoid, trapezoid, acromioclavicular reconstruction (Sports Med Arthrosc Rev 2006;14: ) Acromioclavicular (AC) joint separations are one of the most common shoulder injuries seen in the general orthopedic practice. AC joint injuries occur 5 times more frequently in men than women with the highest incidence occurring in their 20s (43.5%). 1 In the contact athlete, it is the most prevalent shoulder injury. Of shoulder injuries in collegiate football players and National Football League quarterbacks, 41% and 40% (respectively) were AC joint separations. 2,3 The most common mechanism of injury is direct contact to the acromion either by another player or the ground while the arm is in an adducted position. The AC joint is a very strong and resilient joint. A thorough understanding of the anatomy and biomechanics of the joint is helpful when choosing between the different treatment options that are available. Depending on the magnitude of the From the Department of Sports Medicine, The Ohio State University Medical Center, Columbus, OH. Reprints: Julie Y. Bishop, MD, 2050 Kenny Road, Suite 3300, Columbus, OH ( Julie.Bishop@osumc.edu). Copyright r 2006 by Lippincott Williams & Wilkins injury, these treatment options range from nonoperative measures allowing a quick return to preinjury status to operative reconstruction of the joint using various forms of fixation and augmentation. There is a multitude of research available and at times, choosing the appropriate treatment can be confusing and controversial. Treatment should be individualized, taking into account the demands of the specific sport, and needs and function of the patient athlete. The purpose of this paper is to review the anatomy and biomechanics of the AC joint, review the evaluation and diagnosis of acute AC injuries, review the published evidence for treatment choice and then apply this knowledge to aid in the decision making process for treatment. ANATOMY AND BIOMECHANICS OF THE AC JOINT The AC joint is a diarthrodial joint, with an articular surface made up of hyaline cartilage and surrounded by a joint capsule. It contains an intraarticular meniscus homolog, which undergoes rapid degeneration and is no longer functional after the fourth decade. 4 There is only 5 to 8 degrees of motion through the AC joint which is stabilized by static and dynamic stabilizers. 1 The static stabilizers include the AC ligaments (anterior, posterior, superior, and inferior), the coracoacromial (CA) ligament, and the coracoclavicular (CC) ligaments (conoid and trapezoid). The dynamic muscular stabilizers include the trapezius and deltoid. Fibers of both muscles also reinforce the superior AC ligament. The AC joint capsular ligaments are primarily involved in anterior and posterior stability. 5 Transection of the AC joint capsule and ligaments results in significant increases in anterior and posterior translation. In particular, the posterior-superior ligaments have been found to be critical to restraining excessive posterior translation. 6 This posterior instability can cause painful abutment of the posterior clavicle against the anterior portion of the scapular spine. Complete transection of the AC capsule does shift load to the CC ligaments but they are unable to fully compensate for the loss of capsular function. 7 The CC ligaments provide vertical stability and prevent superior and inferior displacement of the clavicle. This complex is made up of the conoid and trapezoid ligaments, which span a distance of 1.1 to 1.3 cm between the coracoid and clavicle. 8,9 The conoid has a more posterior/medial clavicle attachment and the trapezoid attaches anterior and lateral to the conoid. Both Sports Med Arthrosc Rev Volume 14, Number 4, December

2 Bishop and Kaeding Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 ligaments attach posterior to the pectoralis minor insertion on the coracoid. Complete sectioning of the CC ligaments is necessary for a complete AC dislocation to occur with either superior or inferior displacement of the entire scapulohumeral complex. 10 MECHANISM OF INJURY Most AC injuries are the result of direct trauma. For the athlete, it is usually due to either a direct hit by another player or contact with the ground. The arm is typically in the adducted position when direct impact to the acromion occurs. Because of the strength and stability of the sternoclavicular joint, the energy of the impact is absorbed by the AC and CC ligaments. The magnitude of the force determines the severity of the injury. The impact initially injures the AC ligaments. With greater forces, the injury progresses to involve the CC ligaments and then the deltotrapezial fascia. Indirect injuries do occur although not as often. They are due to a fall on the elbow or outstretched arm, causing forces to be transmitted through the humeral head to the acromion. This mechanism tends to only injure the AC ligaments. INJURY CLASSIFICATION Tossy et al 11 and Allman 12 initially classified AC injuries as types I, II, and III. Rockwood et al 1 subsequently added types IV, V, and VI to complete the classification (Fig. 1). A type I injury is a mild injury spraining the AC ligaments while leaving the joint intact. In a type II injury the AC ligaments are torn, while the CC are intact. A type III injury involves complete tearing of both the AC and CC ligaments with 100% dislocation of the joint. A type IV injury is a complete AC dislocation with posterior displacement of the clavicle through or into the trapezius fascia. A type V injury is a complete AC dislocation with 100% to 300% superior dislocation of the clavicle. It can involve significant disruption of the deltotrapezial fascia. The type VI injury involves inferior displacement of the clavicle into a subacromial or subcoracoid position. DIAGNOSIS AND PHYSICAL EXAMINATION The index of suspicion for injury to the AC joint should be high in any athlete complaining of anterior/ superior shoulder pain after a traumatic injury to the shoulder. Twelve percent of dislocations of the shoulder complex involve injuries to the AC joint. 13 Studies of elite football players have found that AC joint separations comprised 40% to 41% of all shoulder injuries. 2,3 Inspection of a type I or II separation may reveal skin abrasions and swelling over the distal clavicle. A large deformity or gross instability is not present. Typically these patients are tender over the AC joint and have pain localized to the AC joint particularly with cross-chest adduction and internal rotation. These maneuvers compress the AC joint and specifically cause pain at that site. In the type III injury, the deltotrapezial fascia is intact, however the joint is dislocated 100%. Thus, the distal end FIGURE 1. Classification of injuries by type. Reprinted with permission from The Shoulder. Vol 1. Philadelphia: WB Saunders, 1998: of the clavicle is prominent and tender (Fig. 2). Instability testing is difficult to perform in the acute situation, but it would show horizontal and vertical instability. Upward FIGURE 2. Type III AC injury. 238 r 2006 Lippincott Williams & Wilkins

3 Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 Acute Traumatic Acromioclavicular Separation pressure on the elbow and arm should reduce the AC joint. A type IV injury will show that the clavicle is displaced posterior and may tent the posterior skin as it is displaced into the trapezius muscle. Entrapment within the trapezius fascia prevents complete reduction of the joint with upward directed pressure. A type V injury presents with a more extreme examination than the type III. The deltoid and trapezius fascia have been stripped from the clavicle, which presents with severe upward displacement, at times tenting the skin. The entire shoulder complex droops owing to the downward displacement of the scapula and humerus as the clavicle is stabilized. Having the patient shrug the shoulders will help differentiate a type III from a type V as a type III AC separation will reduce with this maneuver. A type V will not due to the fascial stripping. A type VI injury is very rare. 14 The clavicle is either subacromial or lodged subcoracoid beneath the conjoined tendon. This injury is often associated with extreme trauma and transient parathesias may be present until the clavicle is reduced. RADIOGRAPHIC EVALUATION Traditional anteroposterior radiographs of the shoulder are often not adequate for thorough evaluation of the AC joint. This area requires one half to one third of the penetration required for the glenohumeral joint, thus these views are often over penetrated. A Zanca view (15- degree cephalic tilt) is recommended as the most accurate for evaluation of the AC joint. The normal width of the AC joint is between 1 and 3 mm and the space naturally decreases with increasing age. 15,16 The CC distance is on average 1.1 to 1.3 cm and an increase of 25% to 50% more than the normal side indicates disruption of the ligaments. 17 The axillary view allows for evaluation of the anterior/posterior position of the distal clavicle with respect to the acromion (Fig. 3). Stress views are primarily used to differentiate between a type II and type III AC separation. However, rarely is this difference clinically significant and the information provided does not outweigh the added time, cost, and discomfort to the patient. A clinically significant AC separation is typically demonstrated easily on routine AP views and on examination of the patient. DECISION MAKING AND MANAGEMENT OF THE ACUTE AC INJURY Treatment of types I, II, IV, V, and VI AC joint separations is relatively straightforward and well established. Types I and II are treated nonoperatively and most athletes have a successful outcome with a full return to play. Types IV, V, and VI are treated early with operative intervention, mostly due to the morbidity associated with prolonged dislocation of the joint and the subsequent soft tissue damage. Treatment of the type III separation remains controversial and recommendations continue to evolve. Prospective studies evaluating operative and nonoperative treatment of these injuries have shown satisfactory results for both with no great advantage of FIGURE 3. Axillary radiograph of AC injury demonstrating posterior displacement of the distal clavicle relative to the acromion. either treatment. Although there is a trend towards nonsurgical intervention, the issue still remains as to whether or not the performance of the overhead athletes may be diminished by the type III separation. NONOPERATIVE TREATMENT It is generally agreed upon that the type I and II injuries should be treated in a nonoperative fashion. This consensus is based on the experience of orthopedists that these injuries do well nonoperatively, thus there has been no significant historical push for a surgical treatment of type I or II injuries. No prospective randomized study has been done. The goal for most athletes with these injuries should be a return to full play within 1 to 4 weeks depending on how much contact is involved in their sport and how much overhead activity their position entails. The main goals of treatment are a return to play with full pain-free range of motion, full strength, and no limitations to activity. Gladstone et al 18 developed a 4 phase rehabilitative program for athletes after an AC separation. The first phase consists of ice and short-term immobilization. A sling may be used for up to 2 weeks. The goals are to decrease pain and inflammation and then gently start range of motion exercises. Active-assisted motion is gradually increased as long as it is relatively pain-free. Elevation in pure abduction is avoided as this r 2006 Lippincott Williams & Wilkins 239

4 Bishop and Kaeding Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 stresses the AC ligament. The athlete is advanced to phase 2 when (1) 75% of motion is regained, (2) there is minimal pain with palpation of the AC joint, (3) manual muscle testing is 4/5 for the deltoid and upper trapezius. Phase 2 involves advancing to full pain-free motion and increasing isotonic strength. Strengthening exercises are focused on the deltoid, trapezius, and rotator cuff. Advancement to phase 3 occurs when the athlete has (1) full range of motion with no pain, (2) no tenderness at the AC joint, and (3) strength that is 75% of the contralateral side. Phase 3 care is directed towards strengthening the shoulder and increasing power and endurance. Plyometric drills and isotonic exercises are used. The patient advances to phase 4 when the phase 3 criteria are met and they have isokinetic strength equal to the opposite side. Phase 4 treatment involves sport-specific drills to allow full return to play. TYPE III INJURIES The treatment of the type III AC separation remains controversial, although the trend is towards nonoperative initial care. In 1974, Powers et al 19 reported that 92% of 116 type III injuries were treated nonoperatively. In 1991, Cox 20 reported that 86% of team physicians were managing type III injuries nonoperatively. The literature has shown that many others have supported nonoperative treatment Rockwood et al 1 reported that nonoperative treatment was especially warranted in those athletes who participated in contact sports in which the risk of reinjury was high. Comparison studies have been performed and many have reported similar results for operative and nonoperative management Larsen et al 27 found in a prospective randomized trial of 84 patients that most patients did as well or better with nonoperative management. A prospective study by Bannister et al 26 found that nonoperative treatment allowed an earlier return to sports and work and restored motion faster. Phillips et al 28 performed a meta-analysis of 1172 patients and found that 88% of the operatively treated and 87% of the nonoperatively treated patients had satisfactory outcomes. Those treated operatively had a higher rate of reoperation and infection whereas those treated nonoperatively had a higher rate of deformity. Pain and motion were not significantly affected or different between the groups. When comparing strength at 2 years followup, Tibone et al 29 found that there was no difference in strength between those treated nonoperatively or operatively. Several others have reported similar findings regarding functional return between the operative and nonoperative groups Thus the evidence does not support the routine surgical treatment of acute type III AC injuries. In lieu of the above-mentioned studies, many do feel that some athletes are more likely to become symptomatic following a type III separation. Although the majority of athletes are initially treated nonoperatively, some change their approach to the overhead throwing athlete. The disruption of the synchronous scapuloclavicular rotation that normally occurs with overhead activity can lead to pain and mechanical symptoms in the overhead throwing athlete. 1 This finding has led some authors to recommend early surgical intervention in the throwing athlete An informal survey of team physicians reported by Nuber and Bowen 36 found that most would consider initial operative treatment for the throwing athlete, particularly a baseball pitcher. As the quarterback position does not require quite the same specific motion, most would elect initial nonoperative treatment. McFarland et al 37 reported that 69% of major-league baseball team physicians would opt for nonoperative treatment in a pitcher. Of the 32 patients reported with a type III injury, 20 were treated nonoperatively and 12 operatively. Eighty percent of the nonoperative group and 91% of the operatively treated group reported full function and pain relief. The evidence for acute surgical treatment of type III AC joint injuries in throwing athletes is not well established. A more controlled randomized prospective study is needed in this group. Timing is an important issue when considering reconstruction of the AC joint. The general consensus has been to treat type III injuries nonoperatively in the athlete. If symptoms persist and the athlete has continued pain and instability after 3 to 6 months, operative intervention may be necessary. Often the pain is due to posterior instability of the distal clavicle, impinging on the anterior aspect of the scapular spine. Thus if the athlete remains symptomatic, the reconstruction can be performed on a delayed basis. However, some studies have indicated that the results may not be as good if the surgery is delayed. Weinstein et al 34 found a trend towards better results when the ligament reconstruction was performed within 3 weeks of injury. Others have found no difference between early and late (greater than 3 weeks from injury) reconstruction. 35 Should one decide to pursue a surgical intervention, the timing of a surgical repair (early vs. late) of a type III AC joint injury is not clear in the literature. Type III injuries that are treated nonoperatively follow the same 4-phase protocol for return to play as outlined above. It is unlikely that the athlete will return as quickly as after a type I or II injury. Sling use continues for a longer period of time, and the overall protocol progresses at a much slower rate. A guarded return to sports is allowed over the subsequent 3 months; however, the athlete is closely watched for any signs of continued pain and instability that may interfere with play. OPERATIVE TREATMENT Acute types IV, V, and VI injuries generally felt to require operative intervention due to the morbidity associated with the severe soft tissue disruption and a persistently dislocated joint. There are no randomized/ prospective studies to support this, but the amount of deformity, tissue damage, and reports of persistent symptoms in patients with these injuries has led to the current consensus that they be treated operatively. There 240 r 2006 Lippincott Williams & Wilkins

5 Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 Acute Traumatic Acromioclavicular Separation has been support in the literature for performing a closed reduction and converting the injury to a type III and treating conservatively. 36 However, concern remains regarding the substantial deltotrapezial fascial stripping that occurs with these types of injuries. In addition to the fascial stripping, type V injuries also carry a high risk of compromise to the overlying skin due to the superior migration of the clavicle. Type VI injuries are exceedingly rare and the possibility of a closed reduction from the subcoracoid position is relatively remote, warranting surgical intervention. Thus, operative management is typically indicated for types IV, V, VI, and the select type III injuries. OPERATIVE TECHNIQUE ISSUES Although there are more than 60 surgical techniques reported for repair and reconstruction of the CC ligaments, no gold standard exist as of yet. Issues regarding fixation and augmentation techniques and graft choice remain as adequate clinical studies to answer these questions have not been performed. Table 1 summarizes studies that have evaluated fixation techniques for complete AC joint separations. Pin fixation has been used across the AC joint, however, this has been fraught with pin breakage, migration, infection, an increased risk of AC arthritis, and the need for hardware removal. Dynamic muscle transfers were once popular, in which the tip of the coracoid with the attached conjoined tendon is transferred to the undersurface of the clavicle. This procedure fails to provide static stability to the joint and is not as anatomic as other techniques. Primary CC fixation was first popularized by Bosworth 17 ; the clavicle was fixed to the coracoid with a screw. Placement of the screw is technically difficult and even when accompanied by ligament repair/reconstruction, the screw still must be removed. Synthetic loops (using wires, sutures, Dacron or Mersilene tapes, and other absorbable and nonabsorbable material) between the coracoid and clavicle have been proposed rather than a screw. 34,38,41,42 However, potential problems include erosion through the clavicle or coracoid, anterior displacement, and the risk of late infection. These techniques rely on the assumption that the ligaments will indeed heal at not only their preinjury length but also their prerupture tensile strength. If they do not heal, the fixation will eventually fail, especially in the high demand athlete. Techniques have been developed which focus on reconstruction of the CC ligaments. The classic Weaver- Dunn procedure involved excision of the distal clavicle and transfer of the CA ligament. 43 The CA ligament is transferred to the distal end of the clavicle by a variety of methods and thus becomes the newly reconstructed CC ligament. It has been shown that the transferred CA ligament does not approach the strength of the intact CC ligament In fact, biomechanical studies have found that the initial strength of the CA ligament transfers is 1/4 that of the normal CC ligaments. 44,45 Therefore, many recommend augmentation with various screws, tapes, and methods of suture fixation between the coracoid and the clavicle. 32,35,36,42,47 50 The goal of an effective augmentation is that it would have a similar strength and stiffness to the intact CC ligaments. The thought is that this augmentation will protect the reconstruction during the early phases of healing. Although failures and complications have been noted with some forms of augmentation, there is overall agreement that augmentation of the CA ligament transfer yields better results. However, no consensus exists as to the optimum form of augmentation. 47 Jari et al 46 looked at the biomechanical function of surgical repair or reconstruction with augmentation of the AC joint after dislocation. In an attempt to control stability in all 3 planes, they looked at CC suture sling fixation, CA ligament transfer with suture fixation, and screw fixation alone. They found that bicortical screw fixation from the clavicle to the coracoid was the only surgical technique that controlled anteroposterior and superior translation. However, this method requires screw removal and in the acute situation does require the assumption that the CC ligaments have adequately healed. They concluded that current techniques did not have the appropriate stiffness to restore stability to the AC joint before healing had occurred. Lee et al 45 looked at various tendon graft reconstructions and found that they were stronger, stiffer, and elongated less that the CA ligament transfers and were stronger than many of the suture-type fixations. Tendon grafts also carry the potential to revascularize, whereas suture augmentation ultimately has the potential for suture failure, regardless of the type. Therefore, incorporation of biologic tissue during healing can potentially improve overall structural properties. Some theorize that the strength of the tendon reconstruction in addition to the primary healing of the torn native CC ligaments may actually yield a higher ultimate strength than even that of the native CC ligaments alone. 45 When tendon graft is used in acute reconstructions it may increase the initial fixation strength and thus may allow more aggressive rehabilitation and earlier return to play. However, which tendon graft to use is not clear as multiple types of allograft and autograft are available. Lee et al 45 found no difference between semitendinosus, toe extensor and gracilis, and reported that the ultimate failure load of all grafts was equivalent to the native CC ligaments. Allograft has the obvious advantage of avoiding the morbidity of graft harvest site. Long-term studies evaluating tendon graft reconstructions are necessary. Recent efforts have focused on reconstructive procedures that are more anatomic to restore function and stability in all directions of motion. Some studies looking at the results of the modified Weaver-Dunn technique have shown compromised results owing to residual subluxation or dislocation. 34,49 The goal of a more anatomic reconstruction is to restore comparable strength to the native CC ligaments thus decreasing the incidence of postoperative subluxation, dislocation, residual pain which will improve overall outcomes. r 2006 Lippincott Williams & Wilkins 241

6 242 r 2006 Lippincott Williams & Wilkins TABLE 1. Summary of Fixation Methods and Findings Authors Study Design Subjects/Materials Methods Findings Bannister et al 26 Therapeutic Study (level I) 60 patients with acute AC dislocation Prospective, controlled, randomized study. Patients divided into surgical and nonsurgical groups Conservative management is best for most acute dislocations, but surgery may benefit severe displacements Larsen et al 27 Therapeutic Study 84 patients with acute AC Prospective, controlled, randomized study. Patients After 13 months, no difference in clinical results Press et al 32 Dumontier et al 35 Galpin et al 25 Kaplan et al 2 MacDonald et al 31 Taft et al 33 Walsh et al 30 Bjerneld et al 21 Kappakas and McMaster 38 Rawes and Dias 24 Tibone et al 29 Weinstein et al 34 Jones et al 39 Wolf and Pennington 40 (level I) Therapeutic Study (level II) Therapeutic Study Therapeutic Study (Level III) Diagnostic Study Therapeutic Study (level V) (level V) dislocations 26 patients with grade III AC joint separations comparing surgical fixation vs. conservative treatment 56 patients with AC dislocations comparing surgical fixation for acute vs. chronic conditions 37 patients with grade III AC joint separations comparing surgical fixation vs. conservative treatment 336 Football players were evaluated for shoulder pathology 20 male patients with complete AC separation 10 uninjured controls 127 patients with acute AC separation 25 patients with grade II or III AC separations 70 patients with acute AC joint separation 20 patients treated for acute AC separation 30 patients treated conservatively for AC dislocation 20 male patients with grade III AC joint dislocation 44 patients with grade III AC joint dislocations 34-year-old, seen 12 mo after surgical reconstruction of a Rockwood type V AC dislocation Technical note divided into surgical and nonsurgical groups Prospective, nonrandomized. Patients divided into surgical and nonsurgical groups Retrospective review. All patients had a ligamentoplasty performed using the CA ligament Retrospective review. Nonoperative treatment was compared with surgical treatment by Bosworth claviculocoracoid screw fixation of complete AC dislocations Physical testing, medical evaluation, and radiographs/mri were evaluated Retrospective review. 10 patients treated nonoperatively, 10 patients treated surgically, 10 uninjured subjects Retrospective review. Surgical and nonsurgical groups were compared 9 of grade III injuries were treated operatively, 8 nonoperatively; all grade II injuries were treated nonoperatively Retrospective review. Patients were examined after conservative treatment All patients treated surgically Patients were reviewed at an average of 12.5 y postinjury Patients were evaluated more than 2 y postinjury, average follow-up was 4.5 y Patients evaluated after surgical reconstruction 27 patients underwent repair for acute injuries and 17 patients underwent reconstructions for chronic injuries Description of surgical technique and presentation of a case using the patient s autogenous semitendinosus tendon Literature review and the description of an arthroscopic reconstruction technique for AC joint dislocation No clinical difference between conservative and surgical treatments Authors now treat only the more severe form of acute dislocation with surgery due to similar results in both groups No clinical difference between conservative and surgical treatments 50% of players had history of shoulder injury, 41% were AC separations, 20% anterior instability, 12% rotator cuff injury Findings indicate nonsurgical treatment is superior in restoring normal shoulder function in 1st year postinjury Operative management was associated with higher rate of complications. No clinical difference between conservative and surgical treatments Grade III surgical patients rated overall outcome below that of those treated conservatively At follow-up, complete separation often caused remodeling with stability of joint Satisfactory results were obtained in 18 patients. Residual deformity was the primary reason for an unsatisfactory rating In all patients reviewed, AC joint remained subluxed or dislocated. With conservative treatment, a good long-term outcome can be expected without restoration of the joint The strength of the shoulder is not significantly affected by conservative treatment of grade III AC dislocations 26 of 27 (96%) early repairs and 13 of 17 (77%) late reconstructions achieved satisfactory results Biocompatibility and low donor site morbidity make this an attractive graft source The procedure provides an anatomically correct and structurally sound reconstruction of CC ligament complex Bishop and Kaeding Sports Med Arthrosc Rev Volume 14, Number 4, December 2006

7 Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 Acute Traumatic Acromioclavicular Separation Although there has been a shift towards the use of tendon grafts for surgical repair of the AC joint, the majority of these were reconstructing the CC ligaments with one structure only. 39,45 They did not account for the individual variance in structure and function of the intact conoid and trapezoid ligaments. Costic et al 51 reported on an anatomic reconstruction using semitendinosus allograft and compared this with the native CC ligament complex. They found it closely approximated the stiffness of the CC ligament complex. Mazzocca et al 52 recently found that an anatomic reconstruction of the orientation of the CC ligaments with a free tendon graft did show significantly less anterior-posterior translation when compared to the modified Weaver-Dunn procedure. Likewise, a recent study by Dimakopoulos et al 53 found that an anatomic double-loop suture repair for the acute AC separation did control anteroposterior and vertical displacement of the clavicle. However, this again did rely on the assumption that the ligaments would heal effectively. SURGICAL TECHNIQUE A saber-type incision is made in Langer s lines, starting just medial and posterior to the AC joint and curving towards the coracoid. A needle-tip bovie is used to control bleeders. The clavicle is palpated and a horizontal incision with the bovie is made across the deltotrapezial fascia to the AC joint. The clavicle is carefully skeletonized, raising full-thickness flaps anterior and posterior. The AC joint is exposed, again with care to raise subperiosteal flaps to allow an anatomic closure. The deltoid is retracted and split in line with its fibers approximately 2 cm distally to the tip of the coracoid. The CA ligament is palpated and localized if a Weaver-Dunn is to be performed. The surgical techniques of the Weaver-Dunn and modified Weaver-Dunn are well described in the literature. 43 In essence, the acromial end of the CA ligament is released from its insertion under the acromion, often with a thin wafer of bone attached, and a Bunnell-type stitch is placed using either Ethibond No. 2 suture (Ethicon, Inc, Somerville, NJ) or No. 2 Fiberwire (Arthrex Inc, Naples, FL). The distal clavicle is excised and two 1.6 mm drill holes are placed in the superior cortex 3 mm from the distal end, exiting into the intramedullary canal. The 2 free ends of the suture are then passed into these drill holes and the clavicle is reduced and the sutures tied. Augmentation of this repair, securing the clavicle to the coracoid is then performed in the method preferred by the surgeon. Arthroscopic techniques for ligament reconstruction have been described in the literature and can be used as an adjunct to open surgery as well. 40,52 If augmentation techniques or passage of a free tendon graft are to be performed, the tip of the coracoid must be well exposed. Blunt, careful dissection is then performed medially and laterally for passage around the coracoid. A curved suture passer or a right-angle-type clamp is helpful to create the pathway around the base of the coracoid. The graft and any augmentation sutures, etc, are then shuttled around the coracoid base. At this point, the clavicle is prepared for the graft, sutures, etc, again based on surgeon preference. Many techniques for suture passage or free tendon graft passage are described in the literature and the surgeon must choose that which he or she feels most confident performing. However, whether a tendon graft or suture-type fixation is used, the same basic principles apply. A graft must be prepared and sized for the corresponding bone tunnels, taking into the account the anatomic origins of the conoid and trapezoid ligaments. Likewise bone tunnels must also be placed for suture augmentation into the clavicle. Care must be used to assure an adequate bone bridge exists between the 2 tunnels. A suture passer is then passed through the tunnels from superior to inferior to capture and shuttle each limb of fixation through its corresponding tunnel (Fig. 4). The clavicle is reduced with upward displacement of the scapulohumeral complex by as assistant and the graft/suture secured (Fig. 5). Often tendon graft fixation is augmented with suture through the same tunnel as well which is tied down separately. Equally important then is the meticulous closure of the deltotrapezial fascia. Nonabsorbable sutures are used and the fascia closed in an interrupted fashion. If necessary, the deltoid can be secured to the clavicle through small drill holes and Mason-Allen type sutures. The subcutaneous tissue and skin and then closed with absorbable sutures and a sling applied with the arm in neutral rotation with an upward force on the arm. POSTOPERATIVE COURSE The patient is placed in a sling for at least 6 weeks postoperatively. The patient must understand the FIGURE 4. Allograft semitendinosus has been passed around the base of the coracoid and each limb shuttled up through the corresponding bone tunnels. Note the adequate bone bridge between the 2 tunnels. r 2006 Lippincott Williams & Wilkins 243

8 Bishop and Kaeding Sports Med Arthrosc Rev Volume 14, Number 4, December 2006 surgical intervention is warranted, many different options exist and much research has been dedicated to developing the best technique. Many recent biomechanical and anatomic studies have helped shed light on this controversial area. The goals of surgery should be to restore the original anatomy and tensile strength of the damaged CC ligaments and provide stability in all directions. FIGURE 5. The graft is then secured, in this case with a biotenodesis screw in each bone tunnel. The graft was then folded over and sutured to itself. A supplemental suture was also shuttled through the tunnels with the graft and tied down as well. The black arrow denotes the graft, the white arrow shows the reduced AC joint. importance of compliance with the sling and is only allowed to come out for supervised physical therapy. Gentle pendulum exercises can be initiated immediately. Passive and active-assisted motions can gradually be instituted. The sling is discontinued between 6 and 12 weeks. At 12 weeks, isometrics are begun and strengthening is instituted between 3 and 5 months. Contact sports are allowed at 6 months; however, peak strength may not be obtained until possibly 9 to 12 months. CONCLUSIONS Injuries to the AC joint are common amongst athletes, in particular contact athletes. The majority of these injuries can be treated nonoperatively with appropriate rehabilitation to allow the athlete an expedient return to preinjury levels of play. Acute type I and II injuries are treated nonoperatively. Acute types IV, V, and VI are managed with surgery. The type III injury is the most controversial. The majority are initially treated nonoperatively, with surgical intervention only when the athlete remains symptomatic after completing a nonoperative course of treatment. 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